Native budworm

Native budworm (Helicoverpa punctigera) activity has been relatively low throughout many regions in recent weeks. In previous years, native budworm have built up in moderate-high numbers by late October, with crops across many parts of Victoria and New South Wales often requiring chemical control. The low numbers observed this year are likely to be caused by climatic conditions. During winter, native budworm breed on flowering plants in the arid inland regions of Queensland, South Australia and New South Wales. These populations then migrate into agricultural regions in late winter and spring. The numbers and timing of these migratory flights are mostly unpredictable as the moths often travel hundreds of kilometres, carried on high altitude wind currents. Higher than normal rainfall across much of the inland breeding grounds this winter has provided plenty of available food for native budworm. It is believed that this has lessened the need to migrate, resulting in fewer flights of native budworm.

Agronomist, Brendan Reinheimer (Elders), reports finding only very low numbers of native budworm caterpillars when checking a number of pulse and canola crops around Birchip, Charlton and Boort, in the Mallee and Northern Country districts of Victoria. Agronomist, Ian Cocking (AGRIvision Consultants), reports a low number of caterpillars present in crops around Quambatook and Swan Hill, in the Mallee district of Victoria. Ian says the low numbers mean chemical control is unlikely to be required in many instances. Adrian Tyler (Tyler’s Hardware & Rural Supplies) also reports only a few native budworm caterpillars present in vetch and bean crops around Rupanyup, in the Wimmera district of Victoria.

In New South Wales, Industry development manager, Trevor Bray (Pulse Australia), reports finding some activity of native budworm moths in vetch and field pea crops near Deniliquin, in the Riverina district. This sighting followed some warm weather in the region just a few days prior. Agronomist, Hayden Lunn (Landmark Mills), has also reported low numbers of native budworm in pea crops between Coleambally and Tocumwal, also in the Riverina district.

Native budworm is a major pest of a variety of crops during spring and early summer, feeding on buds, flowers, fruiting parts and seeds. Larvae grow up to 40 mm long and can be a range of colours (shades of brown, green and orange), usually with darkish strips along the body and bumpy skin with sparse stiff black hairs.

Click here for images of native budworm and refer to PestFacts Issue No. 9 for more information.